Refillable fuse plug



B. A. M ANSH June 27, 1933.

REFILLABLE FUSE PLUG Filed July 21, 1932 A TTORNEY.

Patented June 27, 1933 UNITED STATES BYRON A. MCANSH, OF CHICAGO, ILLINOIS I REFILLABLE FUSE PLUG i Application filed July 21,

This invention relates to electrical-safety fuse appliances of the renewable ifuse type, and more especially to that form of the same in which an indicating plug is automatically released on a blowing or breakage of the fuse member or strip. And this improvement has for its object To provide a structural formation and combination of parts and features in the .10 above mentioned type of fuse plugs, whereby the ready and effective insertions of the fuse strip in a renewable operation is at tained, and with which an efficient electrical contact at the respective ends of the fuse strip .15 is also attained, with a ready release and drop out,of the portions of a blown fuse strip on a separation of the two component members of the sectional enclosing housing of the appliance. V i

To provide a construction of parts wherein an indicating plug normally retained within the plug housing by the fuse strip, is released on a fusing or blowing of the fuse strip, and moves out of the housing to give a visib le or like apparent indication of the changed .39 trating the preferred form of this invention.

Fig. 2 is a horizontal section on line 2-2, Fig. Fig.3 is a detail side elevation of one of the end contact members of the appliance.

Fig. 4 is an elevation of a type of fuse strip adapted for use in the present structure. 1

Fig. 5 is a sectionalelevation of a-simple type or modification 'of: the construction 49 shown in Fig. '1 I Like reference numerals indicate like parts in the several views. c

In this invention the main and outer member 1 of the enclosing housingof the ap- 4 pliance is'formed of a suitable'non-conducting material, having acentra'l-bore that is open at one end for the introduction and reception of the, hereinafter described removable inner membervof the appliance. Said outer member 1 is provided with the usual 1932. Serial No. 623,751.

fixed outer spirally grooved metal shell 2, -Wh1Cl1 providesan attaching means for the appliance and a terminal or end of the elec trical supply system in which the appliance is placed. In this invention the aforesaid outer shell 2, is provided with an inwardly extending flange 2 covering an end of the outer member 1 of the housing, and adapted for electrical conducting contact with the hereinafter described adjacent contact member of the appliance.

-' In the construction shown, the outer housing member 1 is provided with a cap member or portion 3 to provide a closure for each housing end and at the same time enclose and guide the hereinafter described contact member that has engagement with'the fuse-strip of the appliance and in addition carries the indicating plug of the appliance. V I

-- The removable inner'member of the appliance comprises a central stem 4 of the detail construction hereinafter described and an enlarged end portion of a detail construction as follows l I A head or plug 5 of non-conducting material of a size adapted to form a closure for an open end'of the bore or cavity of the outer housing 1-; a contact disk or ring 6 of metal at one end'of the head or plug -5; a manipulating disk 7 of non-conducting material in contact with the ring 6, and having a larger-diameter than said contact ring,- with a view to safety, and a contact button or disk 8 on theexposed face of the manipulatingdisk 7 and electrically 'connected to the contact disk or ring 6 to constitutethe central terminal contact'of the appliance, and as usual in the present form of fuse and like plugs now in general'use, The central stem 4 of the removable member above referred to comprises a tubular stem of non-conducting material that is yieldingly moved in a longitudinal direction in the appliance,by an expansion spring 9 abutting at one end against a bearing flange 10 in the bore of the stem, and at the other end a like bearing in a recess in the'above' described closure head 5, of the inner removable member of the appliance."

; Guidance of the aforesald central stem 4',

' is in place.-

in a longitudinal direction in the appliance is attained by an axially arranged rod 11 having at one end a stop flange or collar 12 to limit the extent of longitudinal movement of the stem 4, while at, its other end sald rod is fixedly attached to the aforesaid head or plug 5 and in the construction shown passes through and attaches together the contact disk 6, and manipulating disk 7 and the contact button 8, to provide electrical connection between the contact disk' ti and-the terminal button 8, aforesaid.

The companion terminal contact member of the contact structure just descrlbed, comprises in the preferred form of the invention shownin Figs. 1 and-'3, a head or block ,13 of metal -or-lik,e electrical conducting mate'- rial adapted for limited longitudinal move-- ment, partly in thebore of the outer housing member :1 and partly in the inner chamber of thecap piece or member 3 and having a marginalend flange '14: for electrical contact with the aforesaid inwardly extending, flange 2' "of the metal enclosing shell of-the outer housing member '1, and preferably through an interposed spring 15 of a similar form, adapted to maintain continued electrical connection between the parts regardlessof a limited movement ofthe head 13 away from the shell flange 2 which may take place in an assembly of the fuse parts. In the construction shown -in Fig. 1 the main portion of said-terminal contact member or head 13 is formed with a central flared recess or cavity 16adapted to receive an end of the fuse strip 17, and have conducting contact therewitlnwith such contact positively and effectivelymaintained by the free end portion of the stem 4- aforesaid entering said recess or cavity 16 and forcibly holding the end of the fuse strip 17 against the flared wall of said recess or cavity without the necessity of the usual additional means usual to fuse plugs of the present type-.-

At its *other end the fusestrip 17 will have lateral flange or bendl'Z adapted for bearing against an end of the non cond-ucting main body and in electrical contact'with the conducting disk or ring6 of the removable member of the fuse plug, when said member In effecting an assembly of the parts shown in Fig.1,"the main member 1, free from the removable member, and with movable contact head 13 and; its plug'lS pushed inwardly, is adapted to receive a fuse strip 17, which is dropped into bore orcavity, with one end thereofresting in-the'flared cavity 16 of the contactehead 13 aforesaid and the other end of the fuse strip resting against an end of the main member 1. The-removable,member of the plug is then'inserted in the bore of the main member to effect through its central stem it, the above mentioned holding an electrical contact engagement of an end of'the fuse strip with the contact head 13 aforesaid. At the same time a like effective hold-V Extending from the aforesaid "movable contact member 13, a centrally arranged plug or stud 18, preferably of non-conducting material, has movement in a central orifice inthe'cap piece 3of'the main member 1, with the end of said plug in a plane with the end or 'top face of said cap in a normal condition of the appliance, in that the contact head 13, is maintained in such normal contact with the terminal flange 3 of the outer member 1-, by the fuse strip action as a holding means against "the tendency of s'aidco'nt'act head to move awa'y from its electrical Contact under the associated sprmg connection theretofo're described.

With a blowing or parting of the fuse strip under an excessive electrical-load, the

aforesaid indicator plu'g 18 has an outward movement to'provid'e *a visible or palpable ind i cation of the-fact that the fuse plug-is in an inopei-ative' or blown condition. Such indicating movement "of plug 18, takes place,

asthetusestrip 1-7 releases-its holding action on the spring of the renewable member of the appliance, to permit said spring to move the stem4,and contaet headglia carrying said ii-reheating plug longitudinally and er feict the described exposure of the indicating P I In the modified construetaen illustrated in Fig; 5, the indicating plug 18 and 'i'nova'ble contact head-13, are emitted and contact between one end of thejfuse strip 17, with the enclosing metallic shell 2 of the outer housing 1 as attained by a central annular flange 2" of the shell 2, with the central stern 4 of the removable member "of the fuse plug having fixed attachment to tli'e head 'or block bit-hat is in fixed association with the Contact disk or ring 6, manipulating disk? and terminal button 8 that forms the terminal connection for the other end of the fuse strip, as in -the preferred construction heretofore described:

Havingthus fully described my invention wh at l claim and "desire to secure by Letters Patent is 1. :A' fuse plug comprising a main housing of nomconductlng material formed with" a contact member adapted in connection with an end of the main housing to secure by holding contact'an end portion of a fuse, strip,

with a central terminal button electrically connected with said contact member, and with a centralstem of non-conducting material the free end of which has adjacent relation Lethe aforesaid terminal flange of the outer shell and adapted to secure by holding contact, the other end of the fuse strip in contact with said terminal flange. v a

2. A fuse plug comprising a main housing of non-conducting,material formed with a central cavity open'at one end and having an outer shell of conducting material provided with a flange extendinginto said cavity at a point remote from the openend of the same to constitute one electrical terminal of the plug, a removable head of non-conducting material, fitting the open end of the aforesaid cavity, a disk of non-conducting material carried on an end of the said head and having on one face a circular contact member of less diameter than said disk and adapted in connection with an end of the main housing to secure by holding contact an end portion of a fuse strip, and on its other face a terminal button electrically connected to said contact member, a central stem of non-conducting material'on said renewable head, the free end of said stem having adjacent relation to the terminal flange of the a outer shell and adapted to secure by holding the other end of the fuse strip in contactwith said terminal flange.

3. A fuse plug comprising, a main housing of non-conducting material formed with a central cavity open-at one end and having an outer shell of conducting material provided with a flange extending into said cavity at a point remote from the open end of the same to constitute one electrical terminal of the plug, a contact head movable longitudinally in the cavity of the mainhousing and formed with flared recess in one face, a removable head of non-conducting material fitting the open end of the aforesaid cavity and provided with a circular contact member adapted in connection with an end of the main housing to secure holding contact an end portion of a fuse strip, with a central terminal button electrically connected to said contact member, and with a central stem of non-conducting material, having a longitudinal tendency under the influence of a spring, with its free end in adjacent relation to the recess of the aforesaid sliding contact head and adapted to secure by holding contact the other end of the fuse strip in said recess.

4. A fuse plug comprising, a main housing of non-conducting material formed with a central cavity open at one end and having an outer shell of conducting material provided with a flange extending into said cavity at a point remote from the open end of the same to constitute one electrical. terminal of the plug, a contact head movable longitudinally in the cavity of the main housing and formed with a flared recess, in oneyface and carrying on its other face an, indicator plug extending out through an orifice in the main housing, a removable head of non-conducting material fltting the end of the aforesaid cavity and provided with a circular contact member adapted in connection with an end of the outer housing to secure by holding contact an end portion of a fuse strip, with a central terminal button electrically connected to said contact member and with a central contact stem of non-conducting material having alongitudinal tendency under the influence of a spring with its free end in adjacent relation to the recess of theaforesaid sliding contact head and adapted tosecure by holding contact the other end of the fuse strip in said recess.

, v5. Afuse plug comprising, a main housing of non-conducting material formed with a central cavity open at one end and having an outer shell of conducting material provided with a flange extending into said cavity at a point remote from the open end of the same to constitute one electrical terminal of the plug, a contact head movable longitudinally in the cavity of the main housing and formed with a flared recess in one face, a spring member of conducting material interposed between said contact head and the flange of the outer shell, a removable head of non-conducting material fitting the open end of the cavity of the main housing and provided with a circular contact member adapted in connection with an end of said housing to secure by holding contact an end portion of a fuse strip, with a central terminal button electrically connected to said circular contact member, and with a central stem of non-conducting material having a longitudi- V nal tendency under the influence of a spring, with 1ts free end in adjacent relation to the recess of the aforesaid sliding contact head and adapted to secure by holding contact the other end of the fuse strip in said recess.

6. A fuse plug comprising, a main housing of non-conducting material formed with a central cavity open at one end and having an outer shell of conducting material provided with a flange extending into said cavity at a point remote from the open end of the same to constitute one electrical terminal of the plug, a contact head movablelongitudinally in the cavity of the main housing and formed witha flared recessinone'face, a re-j movable head of non-conducting material littmg the open end of the cavity of the'main' housing and provided with a circular contact member adapted on connection with an end of the main housing to secure by holding contact an end portion of a fuse strip, with a central terminal button electrically'connected to said contact membenand with a central stem of non-conducting material formed in slida'ble sections, and interposed spring tending to force said section apart longitudinal ly, the upperend of said stem having adja cent relation to the recess of the aforesaid sliding contact head and adapted to secure by holding contact the other end of the fuse strip in said recess. 7 v

7; A fuse plug con1prisiiig,a in'ain housing ofnon-conducting material formed with a central cavity open at one end and having an outer shell of conducting materialpro vided with a flange extending into said cavity at a point remote from the open end of the same to constitute one electrical terminal of the plug, a contact head movable longitudi-- nally in the cavity of the main housing and formed with a flared recess inone face, and carrying on its other face an indicator plug extending out through an orifice in the main housing, a removable head of non-conducting material fitting the open end of the cavity aforesaid removable head, and an interposed 75 spring tending to force said sleeve away from said head, theupp'e'r end of said sleeve having adjacent relation to the recess of the aforesaid sliding contact head and adapted to secure by holding contact the other end of a fuse strip in said recess.

In testimony whereof I hereunto afiifi signature BYRON A. MCANSH'.

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